Giant sigmoid diverticulum: case report and review of the literature.

Giant colonic diverticulum is a rare entity first described in 1946 by Bonvin and Bonte. It may be congenital or acquired and the average age of presentation is 65. There are less than 150 reported cases in the literature. A large abdominal mass was detected during a routine physical examination in an 82-year-old man. CT scan showed a large air-filled mass, barium enema showed multiple sigmoid diverticula, but no communication with the mass was found. A diagnosis of giant sigmoid diverticulum was made, elective sigmoidectomy and resection of the diverticulum was performed with no complications. The clinical picture may be different, varying from asymptomatic to acute abdomen, intestinal perforation or fistula. It can be diagnosed with abdominal X-ray, CT scan, barium enema or MRI, but colonoscopy is not effective. There are two accepted theories of the pathophysiology of this entity: first, a congenital origin and second, that inflammatory diverticula are caused by a perforation with a ball-valve that allows gas to enter, but not to leave the cyst, thus, enlarging the false diverticulum, and progressively destroying the bowel layers, causing secondary fibrosis. Elective treatment is a segmental resection of the affected colon with the diverticulum and in cases of acute abdomen two-stage bowel resection is preferred.